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 LDI_ADD_EVENT_HANDLER 9F "April 9, 2016"
 NAME
ldi_add_event_handler - add NDI event service callback handler

 SYNOPSIS


#include <sys/ddi_obsolete.h>

int ldi_add_event_handler(ldi_handle_t lh, ddi_eventcookie_t ec,
 void (*handler)(ldi_handle_t, ddi_eventcookie_t,
 void *, void *) void *arg, ldi_callback_id_t *id);




 INTERFACE LEVEL

Obsolete

 PARAMETERS
ldi_handle_t lh


Layered handle representing event notification device.



ddi_eventcookie_t ec


Cookie returned from call to ldi_get_eventcookie(9F).



void (*handler)(ldi_handle_t, ddi_eventcookie_t, void *, void *)


Callback handler for NDI event service notification.



void *arg


Pointer to opaque data supplied by caller. Typically, this is a pointer to the
layered driver's softstate structure.



ldi_callback_id_t *id


Pointer to registration id, where a unique registration id is returned.
Registration id must be saved and used when calling
ldi_remove_event_handler(9F) to unregister a callback handler.




 DESCRIPTION

This function is obsolete and is only maintained for compatibility. Use of this
function is strongly discouraged. For equivalent functionality provided by new
interfaces, see ldi_ev_get_cookie(9F) and
ldi_ev_register_callbacks(9F).


The ldi_add_event_handler() function adds a callback handler to be
invoked at the occurrence of the event specified by the cookie. Adding a
callback handler is also known as subscribing to an event. Upon successful
subscription, the handler is invoked when the event occurs. You can unregister
the handler by using ldi_remove_event_handler(9F).


An instance of a layered driver can register multiple handlers for an event or
a single handler for multiple events. Callback order is not defined and should
be assumed to be random.


The routine handler is invoked with the following arguments:
ldi_handle_t lh


Layered handle representing the device for which the event notification is
requested.



ddi_eventcookie_t ec


Structure describing event that occurred.



void *arg


Opaque data pointer provided by the driver during callback registration.



void *impl_data


Pointer to event specific data defined by the framework that invokes the
callback function.




 RETURN VALUES
DDI_SUCCESS


Callback handler registered successfully.



DDI_FAILURE


Failed to register callback handler. Possible reasons include lack of resources
or a bad cookie.




 CONTEXT

The ldi_add_event_handler() function can be called from user and kernel
contexts only.

 SEE ALSO

 ldi_ev_get_cookie (9F),  ldi_ev_register_callbacks (9F),  ldi_get_eventcookie (9F),  ldi_remove_event_handler (9F) 

Writing Device Drivers

 NOTES

Layered drivers must remove all registered callback handlers for a device
instance, represented by the layered handle, by calling
ldi_remove_event_handler(9F) before the layered driver's detach(9E)
routine completes.